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March 3, 1964 C, w BAUGH ETAL 3,122,948

APPARATUS FOR APPLYING RIvETs original Filed sept. 3, 1957 3 Sheets-Sheet 1 March 3, 1964 c. w. BAUGH ETAL 3,122,948

APPARATUS FOR APPLYING RIvETs original Filed sept. s, 1957 s sheets-sheet 2 EE- El INVENTORS. .7 M ,E Zig/55 M/eizgvz March 3, 1964 c. w. BAUGH ETAL 3,122,948

APPARATUS FOR APPLYING RIVETS Original Filed Sept, 3, 1957 5 Shets-Sheet 5 "H l l @il if United States Patent O 3,122,948 APPARATUS FOR APLYlNG RIVET S Charles W. Baugh and Gerald E. Wehlann, Detroit, Mich.,

assigners to Huck Manufacturing Company, a corpuration ef Michigan Original application Sept. 3, 1957, Ser. No. 681,487, now Patent No. 3,629,665, dated Apr. 17, 1962. Divided and this application Dec. 13, 1961, Ser. No. 167,205 Claims. (Cl. 78-46) This invention relates generally to rivets and more particularly to a method and apparatus for applying rivets.

This application is a divisional application of the copending application of Charles W. Baugh et al., Serial No. 681,487, filed September 3, 1957, now Patent Number 3,029,665.

Rivets of one type commonly include a stump or pin having a head and a shank provided with locking grooves. A collar which is first loosely tted on the shank is adapted to be forced into frietional engagement with the shank at the locking grooves by a variety of riveting tools. Many of these tools employ an anvil or sleeve which moves longitudinally over the collar to swage the collar into the locking grooves and depend for a desired operation on a particular collar shape. Furthermore, it is well known that the fatigue life of substantially any connector is increased when a tension pre-load is maintained in the connector, that is, when tie pin is under a tension load when it has been set.

An object of this invention, therefore, is to provide an improved method and apparatus for applying or setting rivets of the above type.

A further object of this invention is to provide a method and apparatus for applying rivets of the above type by crimping the collar into the locking grooves in a manner such that a tension pre-load is maintained in the pin or stump.

Another object of this invention is to provide apparatus for applying rivets of the above type which is adapted for attachment with rivet guns which are now available and which is useable with rivet collars of dilerent shapes.

A further object or this invention is to provide apparatus for applying rivets of the above type which is simple in construction, economical to manufacture, and ell'icient in operation in setting rivets in the desired manner.

Further objects, features and advantages of the above invention will become apparent from a consideration of the following description, the appended claims, and the accompanying drawing in which:

FIG. 1 is a fragmentary longitudinal sectional view of one type of a riveting gun, showing the apparatus of this invention in assembly relation therewith;

FIG. 2 is an enlarged fragmentary sectional View of a portion of the structure shown in FIG. 1, and showing the crimping jaws for the apparatus of this invention in an extended spread position;

FG. 3 is an enlarged longitudinal sectional View, illustrated similarly to FIG. 2, and showing the jaws in a retracted position;

FIG. 4 is a sectional View showing a stump and collar rivet in condition for setting to connect a pair of parts;

FGS. 5, 6 and 7 are views like FIG. 4 of the rivet shown therein, showing the successive positions of the rivet as the apparatus of this invention is applied thereto;

FIG. 8 is a View looking substantially along the line 8 8 in FIG. 3;

FIGS. 9, 10 and ll are sectional Views corresponding substantially to FIGS. 5, 6 and 7 showing a modified form of the apparatus of this invention in assembly relation with a rivet of the pin and collar type and another type of riveting gun; and

FIGS. l2 and 13 are transverse sectional views looking along the lines 12-12 and 13S- 13, respectively, in FIG. 9.

With reference to the drawing, the riveting apparatus of this invention, hereinafter referred to as a crimping mechanism, and indicated generally at 10, is illustrated in FIG. l in assembly relation with a riveting gun 12 of well known type. As best appears in FIG. l, the gun 12 includes a housing 14 and a piston 16 mounted for reciprocating movement within the housing 14 and having a threaded front end portion 18. The piston 16 is formed on opposite sides with recesses 2l), only one of which is shown, for receiving corresponding portions of one end of a fork member 22 supported intermediate its ends 0n a pivot 24 carried on a handle 26 for the gun 12. The opposite end of the fork 22 carries a roller 3G which is adapted to roll between inclined guides 32 and 34 that are movable within the handle 26 toward and away from the pivot 24. It is apparent that on movement of the guides 32 and 34 away from the pivot 24, the fork 22 is swung in a counterclockwise direction about the pivot 24 for moving the plunger 16 in a forward direction. Likewise, when the guides 32 and 34 are moved toward the pivot 24, the fork 22 is moved in a clockwise direction to move the piston 16 rearwardly. A trigger 28 on the handle 26 operates a hydraulic or other mechanism, in a well known manner, to move the guides 32 and 34 in the desired direction.

The crimping mechanism 10 includes a hollow barrel 36 having a tubular inner end portion 38 provided with diametrically opposite ears 40. The barrel 36 also includes a tubular outer end portion 42 having an inner bore section 44 and an outer bore section 46 which is of a slightly larger diameter than the section 44. An intermediate section 48 of the barrel 36 has a bore Sil extended therethrough which is of a reduced size relative to both the bores 44 and 46.

Positioned the outer end portion 42 of the barrel 36 is a tubular crimping collet 52 (FIGS. 2 and 3) having an internally threaded inner end portion 54 slidably supported within the bore section 44. The collet 52 is provided with four slots 56 located outwardly of the inner end portion 54 and terminating at their inner ends in holes 58. The slots 56 are equally spaced and thus divide the collet into four elongated jaws or fingers 6l) (FIG. 8), each of which is of a width corresponding to substantially one fourth of the circumference of the collet 52. Adjacent its outer end 62, the collet 52 is of a unitormly increasing diameter to provide each jaw 6i) with an outwardly inclined outer surface 64 for a purpose to appear later.

inwardly of the outer end 62 of the collet 52, each jaw 6i) has a transversely extended relief groove 66 on its inner side and between the groove 66 and the outer end 62 each jaw is provided with a rounded radially inwardly extended projection or knob 68. An expander plug (not shown) is inserted in the collet 52 prior to heat treating of the collet so that in its linal form, the collet is stressed such that the jaws 641 are spread apart as illustrated in FIGS. 1 and 2. To contract the collet S2 or, in other words, move the jaws 60 inwardly toward each other, it is necessary to move the inner end portion 54 of the collet 52 rearwardly in the inner bore section' 44 to progressively engage the inclined jaw surfaces 64 with the outer end 7 il of the barrel 36, which has a beveled inner surface portion 72 to reduce wear on the jaws 60.

A plunger 74 slidably supported in the inner barrel portion 38 has an elongated stern 76 extended through the reduced bore 50 and threaded into the inner end portion 54 of the collet 52. To move the jaws 6G to fully moved- E apart positions, as shown in FIGS. 1 and 2, the plunger 714 is moved to a stop position engaged with Vthe intermediate barrel portion 48. The extent of movement of the jaws 69 in directions to expand the collet 52 is ofV course adjustable by advancing or retracting the stem 76V within the collet -52 since such adjustment determines the extent of outward movement permitted the jaws 60 by the barrel 36. The contracted position of the collet 52, corresponding to positions of the jaws 69 in which the jaws are moved inwardly toward each other, is illustrated in FIG. 3Y and is defined by the engagement of the inner end portion 514 of the Vcollet S2 with the intermediate barrel portion 48.

In the Vassembly of the crimping mechanism 1t) with the gun 12, the -ban'el 36 is supported on the gun casing 14 in a position in which one of the ears fill is interlocked with the casing 14 and the end portion 18 of the piston 16- is threaded intoy an inner end portion 78 of the plunger 74 as shown in IFIG. l. Tnus, on operation of the gun 12 to retract the piston 16, the jaws 69* are moved inwardly toward each other to the stop position of the collet 52 illustrated in FIG. 3. Conversely, on operation of the gun12 to move the piston 16 outwardly, the jaws 69 are moved apart to the positions illustrated in FIGS. l and 2 corresponding to an expanded condition of the collet 52.

In the operation of the crimping mechanism to set the rivet indicated generally at Si) in FIG. 4, assume that a,

pair of parts or plates 82 and 84 yare to be connected by the rivet Si). The rivet 80 consists of a stump 86, extended through aligned openings `88 in the platesl 82 and 84 and a collar 100 positioned on the stump 86. The stump 86 has a shank 92, which is illustrated as being of asize providingfor an interference iit in the openings 88 `although it is to be understood that such an interference iit is not required and the mechanism 16v is used with rivets in which a more loose t is involved. `In addition, the stump S6 includes a head 9i? located at one end of the' shank 92' and positioned in engagement with the plate 82. Adjacent its terminal end 94, the shank 92 is formed with locing grooves 96 and ridges 98 for a purpose to appear later. The collar 1% is supported on the shank 92 in a position extended about the shank 92 at the grooves 96 and against the plate 84.

The gun 12 is first moved to a position in which. the collet 52 is positioned about the collar 1% with the outer end 62.0f` the collet 52 against the plate 84 as shown in FIG. 5. A coil spring 10:1 positioned within the collet 52 and secured at the inner end thereof to the inner end portion 54 of the collet, has its outer end engaged with the end of the collar 1%. As a result, the `spring 101 acts to exert a yieidable force onA the collar 160 holding the collar against the Vadjacent plate 84. The trigger 28 is then operated to retract the piston 16 to in turn retract the collet S2Y relative to the barrel 36. Concurrently with this manipulation of the trigger 28, forward pressure is exerted on the gun 12 to maintain the end 62 of the collet 52 against the plate l84. As a result of this concurrent manipulation of the gun 12 Iand the trigger 28, the barrel 36 is in eect moved toward the plate 84 to move the jaws 60 inwardly toward each other las illustrated in FIG. 6.

The curved projections 68 on the jaws 60 thus act to squeeze or crimp the collar 106 as shown in FIG. 6 so that the collar is progressively swaged into engagement with the locking grooves 96. By virtue of this swaging, the collar 160 is interlocked with the shank 92 at the grooves 96 and the ridges 98. Continued movement of the barrel 36 toward the plate 84, therefore, acts to further pinch or squeeze the collar 1613 so that the collar material is moved in a direction axially of the collar.

Since the collar is engaged with both the plate 84 and.

the ridges 98, the shank 92 is effectively pulled over the length thereof between the head 9i) and the ridges 98. As a result, the plates 82 and 84 are pulled tightly together to insure a complete pull through of the stump 86 and eliminate any gap between the plates, as shown in FIGS.

i 6 and 7. In the final set position of the rivet S0, the collar has been effectively lengthened as illustrated in FIG. 7 to in turn stretch the shank 92 and apply a tensile pre-load to the stump 86. In other words, by virtue of the curved projections '68 on the jaws 60, the collar material is iirst interlocked with the stump 92 at the ridges 93 and the grooves 96 Ifollowing which the collar material is further expanded or stretched in an axial direction to apply a tensile pre-load to the stump. Such a preload elfectively increases the fatigue life of the rivet Si?, and prevents any loosening of the stump or the collar 106 during use of the parts S2 and 84.

Two looking grooves 96 and ridges 9S are illustrated for the rivet Si? so that the rivet can be used for connecting workpieces 82 and 84 of thicknesses within predetermined limits or grip lengths.

A modified form of the crimping mechanism of this invention, indicated generally at 10a, is illustrated in FIGS. 9-13, inclusive. The mechanism 10a is adapted for assembly with a riveting mechanism of well known type, indicated generally at i, which includes an outer sleeve or anvil member 122 having an inwardly tapered inner surface 124 adjacent its terminal end 126. The

mechanism also includes a plurality of jaws 128 whichV are adapted to -be contracted and moved rearwardly within lpull gun 12 illustrated in lFIG. l ris* associated with the element 13d for selectively moving the element 130y rearwardly within the sleeveV 122.

The crimping mechanism 10a includes a collet 132 having a tubular inner end portion 134 positioned within the sleeve 1.22. The collet 132 is provided with four equally spaced slots 136 extending outwardly Ifrom the inner end portion 134 to divide the collet into four jaws or fingers 140 arranged in `a circular formation transversely ofthe collet 132. Over the length of the jaws 140, the collet i132 is of a uniformly increasing diameter to provide each jaw with an outwardly inclined outer surface 142 for a purpose to appear later. Inwardly of the. outer end .144 of the collet 132, each jaw 141i- `is formed with a transversely extended relief groove it-6V bounded on its inner side by aninwardly inclined `surface 148.

The collet 132 is initially Iheat' treated like the ,collet 52 previously described so that the collet .is stressedv to provide for a natural outward flaring of the jaws 140. To reduce the substantially circular area bounded by the jaws 140, they must be manually moved inwardly toward each other. In the `illustrated embodiment of the invention shown in FIGS. 9-13, this is accomplished by moving the sleeve 122 toward a position completely surrounding the jaws 146. The sliding engagement of the inclined sleeve surface 1124 with the correspondingly inclined jaw surfaces 142 facilitates the movement of the sleeve member 122 outwardly on the collet 132 to contract the jaws.

The spread position of the jaws 140, corresponding to an expanded condition of the collet 132, is illustrated in FIG. 9. The inwardly moved position of the jaws 140, corresponding to a contracted condition of the collet 132, is illustrated in FIG. 11. The natural tendency of the jaws 140 to move away from each other and the cooperating sliding surfaces 124 `and 142 provide #for an automatic movement of the collet 3132 from the FIG.` l1 to the FIG. 9 position whenever the reaction force on the sleeve 122 is released. A set screw 150 carried by the inner end portion 134 of the collet 132 isY guidably supported in Va slot 152 in the sleeve 122 to prevent accidental movement of the collet 132 out of an assembly relation with the sleeve 122.

In the operation of the crimping mechanism 10a to set the lrivet indicated generally `at 154 in FIGS. 10 and lil, and connect a pair of plates 156 and 158, the mechanism 10a is initially moved to the position illustrated in FIG.

9. As shown in FIG. 9, the rivet 154 includes an elongated pin 160 formed with a head 161 and a shank 163 extended through the plates 156 and 158. The shank 163 is formed with locking grooves 162 like the locking grooves 96 formed on the stump 86 and, in addition, is provided with a tail or pull portion 164 formed with pull grooves 166 adapted to be engaged by the jaws 12S on the riveting mechanism 129. Between the locking grooves 162 and the pull grooves 166, the shank 163 has the usual breakneck groove y168. The rivet 154 also includes `a tubular collar 176 supported on the shank 163 at a position extending about the pull grooves 162 and with one end against the plate 158.

With the mechanism a in the position illustrated in FIG. 9, the jaws 149 encircle the collar 170 and the inclined jaw surfaces 148 are in engagement with the outer end 172 of the Collar 170 for maintaining a pressure against the collar 17) to continuously hold the collar in a position against the adjacent plate 158. The gripping jaws -125 are in engagement with the pin 160 at the pull grooves 166 and when t'he riveting mechanism 120 is operated to retract the jaws 1,23 a pull is exerted on the pin 160. The reaction force to this pull is -applied in an opposite direction through the sleeve 122 to the jaws 140. Accordingly, the sleeve 122 is moved toward the plate 153 with the sleeve surface 124 sliding on the jaw surfaces 142 to progressively move the jaws 145 inwardly toward each other as illustrated in FIG. l0.

Each jaw is formed with a curved knob or inward projection 176 which acts in response to inward movement of the jaws 149 to squeeze or crimp the collar 170 as shown in FIG. 10 so that the collar, intermediate its ends, .is progressively swaged into engagement with the shank 163 at the locking grooves 162. By virtue of this swaging, the collar 17@ is interlocked with the pin 160 at the grooves 162.

Continued movement of the sleeve 122 toward the plate 15S, in response to pull of the jaws 12S on the shank 163, acts to further pinch or squeeze the collar 170 so that the collar material is extended in a direction axially of the collar. As best appears in FIGS. 9, 10 and l1, the jaws 140 are of `a length outwardly of the inclined surfaces 14S and relative to the length of the collar 17? such that cle-arance is provided between the outer ends 144 of the jaws 14@ and the plate 15S `during crimping of the collar 179. On crimping movement of the jaws 140, the inclined jaw surfaces 14S ride on the outer end of the collar 176` so as to continually exert the desired force on the collar y179 `for maintaining the collar in position against the plate 158.

The pulling force on the pin 16) provides the desired pull together of the plates 156 and 153 prior to any swaging of the collar `170. After initial swaging of the collar 17? into the grooves 162, continued crimping of the collar provides `for an elongat-ng of lche collar between the grooves 162. and the plate 158. Since the collar is engaged with both the plate 15% and the pin 169 at the grooves 162, this elongating of the collar causes a pulling force to be exerted on the pin between the pin head and the grooves 162. In other words, the collar 170 is lengthened to in turn stretch the pin 166 and apply a tensile pre-load to the pin. Continued pull on the jaws 12S causes the usual fracture of the shank 163 at the breakneck `groove 168. This sequence of operation is insured merely by forming the collar 170 of a material which is of a requisite hardness, without requiring special collar shapes to develop hold off as is the case with most riveting apparatus now in common use. If the collar material is too soft, the collar may be swaged into the locking grooves on the Shank before the plates to be connected have been pulled tightly together or before the pin has been completely pulled through the plate openings. In the event the collar is too hard, the pin 169 may fracture prematurely before the desired swaging has been accomplished.

From the above description, it is seen that this invention provides crimping mechanisms 1li and 10a for applying a collar to the shank of a stump or a pin 'for a rivet. It is apparent that the mechanisms 10 and 10a are not limited to use with a collar of any particular shape. Accordingly, specially shaped collars are not required when setting rivets with the mechanisms 10 and 10a. Furthermore, as a result of the fact that the mechanisms of this invention are not `limited to use with any particular collar shape, they are readily used to salvage improperly swaged collars which have been applied with rivet setting mechanisms of conventional type.

lt is to be understood that while the crimping mechanism y10 has been particularly described with respect to its use with the gun 12, it is useful with any tool which is operable to apply a pull to the plunger 74 to contract the jaws 6%. Also, the mechanism 10a is useable with any rivet setting device which will concurrently apply a pull to the pin 16? and contract the jaws V140.

Although the invention has been described with respect to several embodiments thereof, it is to be understood that it is not to be so limited, since changes can be made therein which are within the scope of this invention as dened by the appended claims.

What is claimed is:

l. Apparatus for setting a rivet of the type including a pin having a shank #with a locking groove extending thereabout and a collar adapted to be supported on the shank at a position opposite the Ilocking groove, said apparatus comprising jaw means adapted to receive the collar and actuable for movement substantially only radially inwardly of the collar into engagement with the outer surface thereof for swaging the collar into interlocking engagement with the shank at the locking grooves, gripping memls for exerting a pulling force on the shank of the pin, and means operable with said jaw means and said gripping means for actuating said jaw means responsively to the pulling force of said gripping means.

2. Apparatus for setting a rivet of the type including a pin having a shank with a locking groove extending thereabout and a collar adapted to be supported on the shank at a position opposite the locking groove, said apparatus comprising jaw means adapted to axially receive the collar and actuable for movement substantially radially inwardly of the collar into engagement with the outer surface thereof for swaging the collar into interlocking engagement with the shank `at the locking grooves, gripping means for exerting a pulling force on the shank of the pin, and means operable with said jaw means and said gripping means for actuating said jaw means responsively yto the pulling force of said gripping means, said jaw means having stop means engageable with one end of the collar for limi-ting the axial movement of the collar inwardly of said jaw means.

3. Apparatus for applying a fastener which includes a pin having a head and a shank and locking grooves formed in the shank at a position spaced from said head and a collm disposed on said shank at a position in radial alignment with said locking grooves, said apparatus compn'sing a tool having a tubular barrel provided with an open end, a tubular collet provided with a plurality of slots extending lengthwise thereof from `one end of the collet and terminating short of the opposite end thereof to form -a plurality of elongated jaws, said jaws being spaced apart circumferentially of said collet and arranged in a spread-apart formation about the axis of said collet so that at said one end thereof said collet is of a diameter greater than the inner diameter of said open barrel end, said collet being supported in said barrel so that said one end thereof projects out of said open barrel end, said collet and barrel being movable relative to each other in an axial direction to provide Afor movement of the collet inwardly of the open end of the barrel so that the barrel moves said jaws radially inwardly of the collet at said one end of the collet, said collet having an annular stop therein concentric with the axis thereof and positionahle aboutsaid pin in engagement with one end of said collar, and 'rounded projections on the radially inner sides of said jaw members at said one end of said collet.

4. Apparatus `for applying a fastener Vwhich includes a pin having a head and a shank and locking grooves formed in the shank at a position spaced from said head and a collar disposed on said shank at a position in radial alignment with said locking grooves, said apparatus comprising a tool having a tubular Ibarrel provided with an open end, a tubularcollet provided with a plurality of slots extending lengthwise there-of from one end of the collet and terminating 'short of the opposite end thereof to form 'a plurality of elongated jaws said jaws Vbeing spaced apart circumferentially of said collet and arranged in a spread apart formation about the axis of said collet so that at saidone end thereof said collet is of a diameter 'g'reaterthan the inner diameter of said open barrel end, said collet bein-g positioned concentrically with-in and supported on 'said banrel so that said one end of the collet projects out of said open barrel end, and gripping means on said tool positioned 'in said barrel and engageable with said shank for exerting a pull on said shank and electing a relative movement of the collet and barrel to provide for movement of the collet inwardly of the barrel so that the barrel moves said jaws radially inwardly ofthe collet at said one end of the collet, said collet having lan annular stop therein concentric with the axis thereof and posit-ionable about said pinin engagement with one end of said collar.

5. Apparatus for applying a fastener which includes a pin having a head and a shank and locking grooves formed in the shank `at la position spaced from said head and a collar `disposed on said shank ait -a position in radial alignment -with said locking grooves, said apparatus comprising a tool Vhaving a tubular barrel provided with of slots extending lengthwise thereof from one end of Y the collet andter-minating short of the opposite end thereof to form a plurality of elongated jaws, said jaws being spaced apart ciroumferentially of said collet and arranged in a spread apart formation about the axis of said collet so that at said one end ythereof said collet is of a diameter greater than the inner diameter of said open barrel end, said collet being positioned .concentrically within and supported on said barrel so ythat said one end of the collet projects out of said openbarrel end, and gripping means on said tool positioned in said barrel yand engageaole with said shank for exertingfa pull on said shank and effecting a relative movement of the collet and barrel to provide for movement of lthe, collet inwardly of the barrel so that the barrel moves said jaws radially inwardly of the collet at said one end of the collet, said collet being for-med on the inner surface rthereof .with an annular stop engageable with one end of a collar to position said one end `of the collet radially opposite an intermediate portion of the collar, and radially inwardly extending rounded projections on said jaw members at said one end of the collet.

References Cited in the tile of this patent UNITED STATES PATENTS 

1. APPARATUS FOR SETTING A RIVET OF THE TYPE INCLUDING A PIN HAVING A SHANK WITH A LOCKING GROOVE EXTENDING THEREABOUT AND A COLLAR ADAPTED TO BE SUPPORTED ON THE SHANK AT A POSITION OPPOSITE THE LOCKING GROOVE, SAID APPARATUS COMPRISING JAW MEANS ADAPTED TO RECEIVE THE COLLAR AND ACTUABLE FOR MOVEMENT SUBSTANTIALLY ONLY RADIALLY INWARDLY OF THE COLLAR INTO ENGAGEMENT WITH THE OUTER SURFACE THEREOF FOR SWAGING THE COLLAR INTO INTERLOCKING ENGAGEMENT WITH THE SHANK AT THE LOCKING GROOVES, GRIPPING MEANS FOR EXERTING A PULLING FORCE ON THE SHANK OF THE PIN, AND MEANS OPERABLE WITH SAID JAW MEANS AND SAID GRIPPING MEANS FOR ACTUATING SAID JAW MEANS RESPONSIVELY TO THE PULLING FORCE OF SAID GRIPPING MEANS. 